Achilles tendon rupture is the most common injury involving a tear in a tendon. It commonly occurs as a sports injury during explosive acceleration, for example, while pushing off or jumping up.
Treatment of Achilles tendon rupture is typically divided between operative and non-operative management, each of which involve holding the foot in a plantar-flexed position and then gradually lengthening (stretching) the tendon as it heals and strengthens.
Operative management involves a surgical operation where the ruptured tendon is sutured back together at the point of rupture, and the leg is then placed into a cast. When the leg is placed in the cast, the foot is pointed downward (in an equinus position). As the healing progresses, the equinus position is then gradually decreased (requiring removal of the original cast, and recasting with the newly decreased equinus position).
Non-operative management typically involves wearing a cast or walking boot, which allows the ends of the torn tendon to reattach themselves on their own. In the non-operative option, the foot is pointed downwards, with the help of heel wedges or insoles, which are placed in the walker boot or cast. The height of the heel wedges or insoles is then incrementally decreased as the process of healing progresses.
Studies have shown that patients have quicker and more successful recoveries when they are allowed to move and lightly stretch their ankle immediately after surgery. To keep their ankle safe while healing, these patients can use a removable boot while walking and/or doing daily activities.
In either the operative or non-operative situation, existing methods for repairing the Achilles tendon can cause unwanted changes in stretching the length of the Achilles tendon, such that the risk of re-rupture of the tendon is increased. Additionally, existing methods for Achilles tendon repair can be inconvenient and uncomfortable to implement. For instance, the fit between conventional Achilles heel wedges and the foot tends to be rather unnatural, causing the user to feel unstable and apply additional and possibly harmful stress on the foot. Conventional Achilles heel wedges also lack overall usability, including a lack of consistency in the heel and foot position.